Intrasynovial Digital Anesthesia in Trigger Finger

Trigger finger is a common disease of the hand involving swelling and inflammation of the tendon which flexes a finger, causing catching, locking, and/or pain. Trigger finger is typically treated by hand surgeons with a steroid injection through the front/palm side of the hand into the area near the tendon (i.e., at the base of the affected finger). This steroid injection is often combined with a local anesthetic (numbing agent) to help reduce short-term pain from the injection. However, the front/palm side of the hand is known to be very sensitive, and the steroid injection can be quite painful as the needle pierces the front/palm skin. To reduce the pain of steroid injections for trigger finger, a different approach involves performing the injection from the back/dorsal side of the hand, which is thought to be less sensitive (and therefore less painful) than the front/palm side of the hand. This technique is sometimes used and has been previously studied, but it is not clear if it can offer less injection-related pain than standard treatment. Accordingly, this study will be comparing short-term injection-associated pain between front/palm side and back/dorsal side steroid injections for trigger finger. The study will also seek to understand what area of the hand is numbed by the anesthetic when doing a front/palm side injection versus a back/dorsal side injection of the hand. Overall, the investigators hypothesize that back/dorsal side injections will be less painful than front/palm side injections for trigger fingers and that the area of numbing from the anesthetic will be equivalent between both types of injections.